in Great Britain and United States, formal accusation issued by a legislature against a public official charged with crime or other serious misconduct. In a looser sense the term is sometimes applied also to the trial by the legislature that may follow. In other countries, impeachment may refer to the removal of a public official from office instead of the accusation. Impeachment developed in England, beginning in the 14th cent., as a means of trying officials suspected of dereliction of duty. The English procedure was for the House of Commons to prosecute by presenting articles of impeachment to the House of Lords, which rendered judgment. Any penalty, including death, might be inflicted. The impeachment (1787) and trial (1788–95) of Warren Hastings was among the last of the English cases.

In the United States impeachment of public officials is provided for in the federal government and in most states. In federal matters the U.S. Constitution gives the House of Representatives the power to impeach civil officers of the United States, including the President and Vice President, but not including members of Congress. Impeachments are tried by the Senate, with the concurrence of two thirds of the members present needed for conviction. The sole penalties on conviction are removal from office and disqualification from holding other federal office; however, the convicted party is liable to subsequent criminal trial and punishment for the same offense.

There have been 19 impeachments tried by the Senate and eight convictions. Three of the best-known cases, which did not result in conviction, were those of Supreme Court Justice Samuel Chase, President Andrew Johnson, and President Bill Clinton (see Lewinsky scandal). In 1974 the Judiciary Committee of the House of Representatives voted to bring impeachment charges against President Richard Nixon (see Watergate affair), but Nixon resigned before the House took action.